Biology

Cell Cycle and Chromosomes

1,348 Questions

Explore a curated list of questions covering the cell cycle, mitosis, and meiosis. Topics include DNA replication, chromosomal structures, and genetic disorders. This material is essential for students preparing for biology and general science competitive exams.

Cell cycle eventsDNA replicationMeiosis processChromosomal structuresGenetic disorders

Cell Cycle and Chromosomes Questions

Multiple choice

The division of nucleus is called _____.

  1. chromosome

  2. mitochondria

  3. karyokinesis

  4. lysosome
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Karyokinesis refers specifically to the division of the cell nucleus during mitosis. The term comes from Greek: "karyon" meaning nucleus and "kinesis" meaning movement/division. Chromosomes are the structures that divide, but the process itself is called karyokinesis.

Multiple choice

Organisms with the highest and the least number of chromosomes are _____________, respectively.

  1. Tympanoctomys barrerae and Myrmecia pilosula

  2. Myrmecia pilosula and Ophioglossum reticulatum

  3. Ophioglossum reticulatum and Myrmecia pilosula

  4. Tympanoctomys barrerae and Drosophila melanogaster

  5. Ophioglossum reticulatum and Tympanoctomys barrerae
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Ophioglossum reticulatum (2n = 1260): Highest known number of chromosomes in any life form. Myrmecia pilosula (2n = 2): 2 for females, males are haploid and thus have one; smallest number of chromosomes among all organisms.

Multiple choice

Regarding cancer genome sequencing, which of the following statements is INCORRECT?

  1. Cancer genome sequencing is the whole genome sequencing of a single, homogeneous or heterogeneous group of cancer cells.

  2. Cancer genome sequencing involves direct sequencing of primary tumor tissue.

  3. Cancer genome sequencing is not limited to WG sequencing.

  4. Cancers are homogeneous populations of cells.

  5. Cancer genome sequencing provides clinically relevant information in patients with rare tumor types.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Cancer genome sequencing is the whole genome sequencing of a single, homogeneous or heterogeneous group of cancer cells. It is a biochemical laboratory method for the characterisation and identification of the DNA or RNA sequences of cancer cell(s).

Multiple choice

Polysomy of sex chromosomes in an individual is induced by successive nondisjunctions in meiosis I and II. Polysomy in which of the following chromosomes causes squamous cell carcinoma in human beings?

  1. Chromosome 17

  2. Tetrasomy 18p

  3. Tetrasomy 9p

  4. Chromosome 7

  5. Trisomy 21
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In squamous cell carcinoma, a protein from the epidermal growth factor receptor (EGFR) gene is often overexpressed in conjunction with polysomy of chromosome 7, so chromosome 7 can be used to predict the presence of EGFR in squamous cell carcinoma.

Multiple choice

The structural abnormalities of chromosome associated with Wolf-Hirschhorn syndrome is

  1. deletions

  2. duplications

  3. the Robertsonian translocation

  4. isochromosome

  5. inversions
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Here a portion of the chromosome is missing or deleted. Known disorders in humans include Wolf-Hirschhorn syndrome, which is caused by partial deletion of the short arm of chromosome 4; and Jacobsen syndrome, also called the terminal 11q deletion disorder.

Multiple choice

Puffs in the salivary gland chromosomes are the sites of

  1. RNA synthesis

  2. DNA duplication

  3. DNA synthesis and destruction

  4. Protein synthesis
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Puffs in polytene chromosomes (such as those found in salivary gland chromosomes of Drosophila) are sites of active RNA synthesis, specifically transcriptional activity. These puffs represent regions where the chromatin has decondensed to allow gene expression. They are not sites of DNA duplication or protein synthesis - those processes occur elsewhere in the cell cycle.

Multiple choice

The techniques of chromosomal jumping and chromosomal walking are useful in the identification of which of the following?

  1. Contigs

  2. Concatemer

  3. Physical location of markers

  4. Correct ordering of yeast artificial chromosome

  5. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

(continuous fragments ) are clones containing neighbouring DNA fragment having an overlapping regions. Contigs greatly facilitate mapping and ultimately the correct alignment of base sequence data.

Multiple choice

Genome is a:

  1. set of haploid chromosomes found in each nucleus of a given species

  2. total number of chromosomes found in an individual

  3. total number of genes required for an expression

  4. total number of genes on a chromosome
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A genome is defined as the complete set of haploid chromosomes found in each nucleus of a given species. It represents the complete genetic material of an organism. Option A correctly describes the genome as the haploid chromosome set. Option B refers to the total chromosome number (2n), not the genome.